Brain Stimulation最新文献

{"title":"Non-invasive modulation of brain activity and behavior by transcranial radio frequency stimulation","authors":"Omid Yaghmazadeh ,&nbsp;Leeor Alon ,&nbsp;Tanzil M. Arefin ,&nbsp;Zakia Ben Youss ,&nbsp;Jiangyang Zhang ,&nbsp;György Buzsáki","doi":"10.1016/j.brs.2026.103032","DOIUrl":"10.1016/j.brs.2026.103032","url":null,"abstract":"<div><h3>Background</h3><div>Achieving non-invasive, targeted modulation of deep brain tissue remains a major challenge in neurotechnology. Current non-invasive brain stimulation methods—such as transcranial electrical (TES), magnetic (TMS), and focused ultrasound (TFUS) stimulation—suffer from limitations in spatial focality, penetration depth, or skull-related distortions. Radio frequency (RF) energy, which penetrates biological tissue effectively, offers an alternative avenue for neural modulation. This study introduces Transcranial Radio Frequency Stimulation (TRFS) as a novel, non-invasive neuromodulation technique that leverages RF-induced thermal effects to modulate neural activity in vivo.</div></div><div><h3>Methods</h3><div>We developed a custom RF stimulation system using 945 MHz stub antennas optimized for localized brain heating in mice. Using our unique experimental setup, we developed and tested two operational modes of TRFS:Pristine mode: RF stimulation applied to intact brain tissue.RF-genetics mode: RF stimulation applied to brain regions virally transduced to overexpress the thermosensitive TRPV1 ion channel.</div><div>Neural activity was recorded using metal-free one-photon fiber photometry with GCaMP calcium indicators. Behavioral effects were assessed through a rotational test in freely moving mice after MK-801-induced hyperlocomotion. Local temperature changes were monitored by optical thermometry.</div></div><div><h3>Results</h3><div>In pristine mode, RF exposure induced temperature rises leading to dose-dependent suppression of cortical parvalbumin (PV) interneuron activity. This neural suppression translated behaviorally into a unilateral rotational bias ipsilateral to the stimulated hemisphere in hyperlocomotive freely moving mice.In RF-genetics mode, RF stimulation of TRPV1-overexpressing regions produced temperature-dependent excitation of neural activity once local change in temperatures exceeded ΔT ≈ 1.5 °C. Behaviorally, this excitation reversed the direction of rotation in hyperlocomotive freely moving mice, yielding a contralateral bias.</div></div><div><h3>Conclusions</h3><div>TRFS represents a conceptual advance in neuromodulation, uniting the inherent capability of RF energy to target deep brain tissue with the biophysical reliability of thermal modulation. TRFS applications are bimodal, capable of influencing the pristine brain by suppressing the activity of specific neuronal populations in targeted regions, or of exciting selectively transfected neural ensembles expressing thermosensitive TRPV1 ion channels. The latter modality, first introduced here, represents a novel concept termed “RF-genetics.” TRFS represents a promising platform for next-generation non-invasive brain stimulation with potential translational applications in treating various neurological and psychiatric disorders.</div></div>","PeriodicalId":9206,"journal":{"name":"Brain Stimulation","volume":"19 2","pages":"Article 103032"},"PeriodicalIF":8.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145997356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A nonlinear relationship of evoked responses following charge-balanced single-pulse electrical stimulation with varying pulse widths","authors":"Isabel A. Danstrom ,&nbsp;Joshua A. Adkinson ,&nbsp;Zoe Liu ,&nbsp;Meghan E. Robinson ,&nbsp;Denise Oswalt ,&nbsp;Garrett P. Banks ,&nbsp;Atul Maheshwari ,&nbsp;Lu Lin ,&nbsp;Ben Shofty ,&nbsp;Mohammed Hasen ,&nbsp;Alica Goldman ,&nbsp;Eleonora Bartoli ,&nbsp;Sarah R. Heilbronner ,&nbsp;Kelly R. Bijanki","doi":"10.1016/j.brs.2026.103049","DOIUrl":"10.1016/j.brs.2026.103049","url":null,"abstract":"<div><h3>Background</h3><div>Single-pulse electrical stimulation (SPES) can help guide neuromodulation therapy in an iterative process to reveal ideal circuits and degrees of engagement. Understanding the relationship between parameter input and neural output will be necessary both to build informative models of the brain's functional connectivity and to improve responses to stimulation-based neuromodulation therapies. Modulating pulse width alters the total charge delivered to neural tissue and is thought to selectively activate fibers with different diameters, potentially shifting therapeutic thresholds. The anterior cingulate cortex (ACC) and orbitofrontal cortex (OFC) are of great clinical relevance to the pathophysiology and treatment of neuropsychiatric disorders.</div></div><div><h3>Objective</h3><div>To provide empirical evidence for the impact of pulse width on pulse-evoked responses and promote the ability to modify specific circuits.</div></div><div><h3>Methods</h3><div>We measured evoked response robustness, peak amplitude, and latency to peak amplitude from depth electrode contacts in 20 epilepsy patients undergoing intracranial monitoring for treatment-refractory epilepsy.</div></div><div><h3>Results</h3><div>A nonlinear relationship between pulse width with evoked potential robustness was determined. Pulse width modulation is further shown to be distance-dependent, with distant connections responding maximally to a shorter pulse width.</div></div><div><h3>Conclusion</h3><div>These results emphasize the importance of input stimulation parameters on cerebro-cerebral evoked potential (CCEP) response magnitude and consistency and are a step towards guiding selective engagement of specific fiber populations for both research and clinical settings.</div></div>","PeriodicalId":9206,"journal":{"name":"Brain Stimulation","volume":"19 2","pages":"Article 103049"},"PeriodicalIF":8.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146137302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing and assessing multichannel TMS focality","authors":"Ole Numssen ,&nbsp;Carla W. Martin ,&nbsp;Torge Worbs ,&nbsp;Axel Thielscher ,&nbsp;Konstantin Weise ,&nbsp;Thomas R. Knösche","doi":"10.1016/j.brs.2026.103054","DOIUrl":"10.1016/j.brs.2026.103054","url":null,"abstract":"<div><h3>Background</h3><div>Multichannel transcranial magnetic stimulation (mTMS) enables electronic steering of induced electric fields across multiple cortical targets without physical coil repositioning, addressing key limitations of conventional single-channel TMS (sTMS). However, determining optimal input currents for focal stimulation remains challenging, and different mTMS systems have not been systematically compared under realistic hardware constraints.</div></div><div><h3>Objective</h3><div>To develop an user-centric framework for optimizing and assessing mTMS focality by introducing a generic optimization algorithm, establishing meaningful quality metrics, and comparing mTMS coil arrays with traditional single-channel TMS across cortical targets.</div></div><div><h3>Methods</h3><div>We developed a fast optimization framework incorporating target E-field constraints via parametrization of degenerated hyperellipsoids, explicitly integrating current-rate limits, for example from stimulator electronics and coil heating. Using high-resolution finite-element models of nine individual brains, we compared two mTMS designs (5-channel planar and 6/12-channel spherical systems) with standard sTMS figure-of-eight coils through E-field simulations. Three complementary metrics quantified stimulation quality: Focality, Target2Max, and OverstimulatedArea.</div></div><div><h3>Results</h3><div>Despite using a single optimized placement for all region-of-interest targets, mTMS achieved focality comparable to repositioned single-channel TMS in this <em>in-silico</em> study. For superficial targets, single-channel TMS showed slightly better stimulation, but for deeper cortical targets (&gt;25 mm skin-cortex distance), mTMS performed similarly. More mTMS channels improved focality but required stronger current-rate constraints. The planar design performed better for deeper targets, while spherical designs improved with additional channels.</div></div><div><h3>Conclusion</h3><div>mTMS systems demonstrate remarkable performance comparable to standard TMS, enabling efficient multi-target stimulation without repositioning. Our open-source framework provides practical tools for designing and evaluating mTMS systems, supporting goal-directed mTMS development and effective application.</div></div>","PeriodicalId":9206,"journal":{"name":"Brain Stimulation","volume":"19 2","pages":"Article 103054"},"PeriodicalIF":8.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146197377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neural mechanisms of tDCS: Insights from an in-vivo rodent model across a range of electric field strengths","authors":"Liyi Chen ,&nbsp;Alireza Majdi ,&nbsp;Boateng Asamoah ,&nbsp;Myles Mc Laughlin","doi":"10.1016/j.brs.2026.103053","DOIUrl":"10.1016/j.brs.2026.103053","url":null,"abstract":"<div><h3>Background</h3><div>Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique that uses low-amplitude currents to generate low electric fields in the brain, influencing cognition, motor skills, and behavior. Despite its potential, the neural mechanisms underlying tDCS remain unclear, in part because many prior studies have used electric field strengths (10–40 V/m) in animal models that exceed those typically achieved in humans.</div></div><div><h3>Objective</h3><div>To better characterize how cortical neurons respond across a range of electric field strengths, we developed an in-vivo rat model to examine the effects of both low and high electric fields.</div></div><div><h3>Methods</h3><div>Currents of 0.005–0.3 mA were applied in 9 rats, generating electric fields of 0.5–35 V/m in the somatosensory cortex. In an anesthetized rat model, we recorded neural activity across cortical layers with a multichannel silicone probe. Somatosensory evoked potentials (SSEP) elicited by foot shocks were recorded, and spike waveforms were used to distinguish regular spiking (RS) and fast-spiking (FS) neurons.</div></div><div><h3>Results</h3><div>Anodal tDCS was associated with SSEP hyperpolarization in superficial cortical regions and depolarization in deeper regions, with cathodal stimulation producing an asymmetric reversal of this pattern. Changes in spiking activity were observed in RS neurons at lower electric fields, whereas higher field strengths were required to influence spiking activity in FS neurons. Across measures, effect magnitudes scaled with electric field strength and were well described by linear mixed-effects models. Changes in spiking activity were correlated with changes in SSEP polarity.</div></div><div><h3>Conclusion</h3><div>These findings demonstrate that electric field–dependent modulation of cortical activity can be detected in vivo across a wide range of stimulation intensities, including weak fields comparable to those induced by human tDCS, although effects are substantially larger at higher field strengths. This work provides direct in-vivo evidence linking cortical polarization to changes in neuronal spiking and helps constrain mechanistic interpretations of tDCS effects observed in humans.</div></div>","PeriodicalId":9206,"journal":{"name":"Brain Stimulation","volume":"19 2","pages":"Article 103053"},"PeriodicalIF":8.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146197368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cerebellar functional reorganization after intermittent theta burst stimulation over vermis on balance recovery in subacute stroke patients","authors":"Guilan Huang ,&nbsp;Zhiyong Zhao ,&nbsp;Daoran Wang ,&nbsp;Li Bian ,&nbsp;Kai Zheng ,&nbsp;Xia Lu ,&nbsp;Xin Wang ,&nbsp;Caili Ren ,&nbsp;Ying Shen","doi":"10.1016/j.brs.2026.103055","DOIUrl":"10.1016/j.brs.2026.103055","url":null,"abstract":"<div><h3>Background</h3><div>This study aims to investigate whether intermittent theta-burst stimulation (iTBS) over the cerebellar vermis enhances balance recovery in subacute stroke, and examine the underlying neural mechanisms.</div></div><div><h3>Methods</h3><div>Fifty-two patients with subacute stroke and balance impairment were randomized to receive either three weeks of iTBS (n = 26) or sham stimulation (n = 26). The primary outcome was the Berg Balance Scale (BBS). Secondary outcomes included additional motor function measures and surface electromyography (sEMG). Clinical assessments were conducted at baseline and at weeks 1, 2, 3, and 6 after treatment onset. sEMG and resting-state functional MRI were acquired before and after the intervention. Seed-based functional connectivity (FC) of the cerebellar vermis was analyzed using a 2 × 2 mixed-effects ANOVA. Associations between changes in BBS (ΔBBS) and FC alterations were examined using Pearson correlation analyses. Patients were further stratified into subgroups based on the direction of FC change (increase vs. decrease) to characterize distinct clinical and neural response patterns.</div></div><div><h3>Results</h3><div>Compared with the sham group, patients receiving iTBS showed significantly greater improvements in balance, accompanied by increased sEMG activation of trunk and proximal lower-limb muscles, with effects sustained at follow-up. FC analyses revealed enhanced connectivity between Vermis X and bilateral occipitotemporal cortices, which was positively correlated with balance improvement (ΔBBS). Subgroup analyses identified distinct clinical and neural profiles: the FC-increase subgroup demonstrated sustained functional gains and enhanced cerebello-frontal connectivity, whereas the FC-decrease subgroup exhibited short-term improvement and reduced intracerebellar connectivity.</div></div><div><h3>Discussion</h3><div>These findings indicate that cerebellar vermis–targeted iTBS facilitates balance recovery after subacute stroke through reorganization of cerebello-visual networks. Subgroup-specific patterns further highlight heterogeneous intracerebellar and cerebello-frontal plasticity, supporting the notion of patient-specific network pathways underlying the therapeutic effects of cerebellar stimulation.</div></div>","PeriodicalId":9206,"journal":{"name":"Brain Stimulation","volume":"19 2","pages":"Article 103055"},"PeriodicalIF":8.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146225611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of electroconvulsive therapy on neural oscillations in schizophrenia: A magnetoencephalography resting-state study","authors":"Yuanhao Li ,&nbsp;Yuru Ling ,&nbsp;Yuejun Li ,&nbsp;Xinyu Fang ,&nbsp;Xiangrong Zhang","doi":"10.1016/j.brs.2026.103062","DOIUrl":"10.1016/j.brs.2026.103062","url":null,"abstract":"<div><h3>Objective</h3><div>Schizophrenia is a complex, chronic mental disorder, and pharmacologic treatment alone is often insufficient. Electroconvulsive therapy (ECT) is a rapid-acting and widely employed physical intervention for schizophrenia, yet its underlying mechanisms remain elusive. The present study aims to elucidate how ECT modulates brain activity in patients with this disorder.</div></div><div><h3>Methods</h3><div>A total of 26 patients with schizophrenia scheduled for ECT and 24 age- and sex-matched healthy controls were recruited. Resting-state magnetoencephalography (MEG) data and clinical assessments, including the Positive and Negative Syndrome Scale (PANSS) and Montreal Cognitive Assessment (MoCA), were acquired at baseline for patients with schizophrenia, and were repeated after the 3rd and 6th sessions of ECT.</div></div><div><h3>Results</h3><div>We found that, at baseline, patients exhibited characteristic abnormalities: elevated delta power, reduced alpha power, and a slower individual alpha peak frequency (IAPF) compared to the healthy controls. Following ECT, brain activity evolved in a gradual but consistent manner—slow-wave (delta and theta) power increased, whereas fast-wave (alpha, beta, and gamma) power declined. Importantly, the reduction in beta power over the bilateral prefrontal and right central cortices was significantly associated with the amelioration of positive symptoms in patients with schizophrenia.</div></div><div><h3>Conclusions</h3><div>Our findings suggest that ECT may induce a profound, progressive therapeutic shift in the brain's electrophysiological state, characterized by a spectral rebalancing toward slow-wave dominance. The selective suppression of prefrontal/central beta power appears to be a key neurophysiological correlate of clinical improvement, providing a putative mechanistic target for optimizing ECT protocols.</div></div>","PeriodicalId":9206,"journal":{"name":"Brain Stimulation","volume":"19 2","pages":"Article 103062"},"PeriodicalIF":8.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147343374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unilateral online ultrasound stimulation of early visual cortex suppresses responses to contralateral visual stimuli","authors":"Suraya Dunsford ,&nbsp;Keith Murphy ,&nbsp;Ema Darrieutort ,&nbsp;Elsa Fouragnan ,&nbsp;Giorgio Ganis","doi":"10.1016/j.brs.2025.103023","DOIUrl":"10.1016/j.brs.2025.103023","url":null,"abstract":"<div><h3>Introduction</h3><div>Transcranial ultrasound stimulation (TUS) shows great promise for inducing neuroplastic changes that persist long after stimulation. Evidence of stimulation-locked (online) neural changes would enable the development of closed-loop application of TUS. However, such responses have been difficult to distinguish from coincident neural activity caused by auditory and somatosensory effects of TUS.</div></div><div><h3>Methods</h3><div>To dissociate genuine online neuromodulatory effects from peripheral confounds, we leveraged the contralateral retinotopic organization of the early visual cortex in nineteen subjects. Using a hemifield visual stimulation paradigm combined with high-precision, functional MRI-guided TUS, we applied TUS to the left early visual cortex while participants viewed checkerboards presented in the left or right visual hemifield. Randomized delivery of TUS on half of the trials enabled within-subject comparisons of hemisphere-specific, pattern-locked visual evoked potentials (VEPs) across stimulated and unstimulated hemispheres, as well as across visual-stimulus and no-stimulus conditions.</div></div><div><h3>Results</h3><div>TUS to the left visual cortex reduced mean VEP amplitude over the stimulated (left) hemisphere for right-hemifield (contralateral) stimuli. No such reduction appeared at the symmetric right-hemisphere sites for left-hemifield stimuli. The degree of online suppression correlated positively with target engagement, estimated by modelling the TUS field that accounted for inter-individual heterogeneity in skull transmission and its overlap with the fMRI-defined target. This relationship suggests that greater target engagement is reliably associated with stronger TUS-induced neural modulation.</div></div><div><h3>Conclusions</h3><div>These findings provide clear evidence of online, spatially specific TUS-induced neural modulation, dissociated from peripheral confounds. This approach establishes a robust framework for future studies aiming to map the TUS parameter space in real time by leveraging topographic organization to control for peripheral confounds, and supports the development of closed-loop neuromodulation protocols.</div></div>","PeriodicalId":9206,"journal":{"name":"Brain Stimulation","volume":"19 2","pages":"Article 103023"},"PeriodicalIF":8.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145965328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Postictal agitation is associated with brain-wide postictal microstructural changes after electroconvulsive therapy-induced seizures","authors":"Joey P.A.J. Verdijk ,&nbsp;Tonia A.L. van Dijk-Schouten ,&nbsp;Julia C.M. Pottkämper ,&nbsp;Laurens A. van de Mortel ,&nbsp;Freek ten Doesschate ,&nbsp;Sven Stuiver ,&nbsp;Maxime Chamberland ,&nbsp;David G. Norris ,&nbsp;Michel J.A.M. van Putten ,&nbsp;Jeannette Hofmeijer ,&nbsp;Guido A. van Wingen ,&nbsp;Jeroen A. van Waarde","doi":"10.1016/j.brs.2026.103031","DOIUrl":"10.1016/j.brs.2026.103031","url":null,"abstract":"<div><h3>Background</h3><div>Electroconvulsive therapy (ECT) is effective in depression, but associated with postictal agitation. Mechanisms of postictal symptoms are largely unclear. We studied whether postictal symptoms are related to immediate postictal diffusivity changes.</div></div><div><h3>Methods</h3><div>In a randomized cross-over clinical trial, we acquired diffusion tensor imaging (DTI) scans before the ECT-course and three times immediately postictally in 22 patients. In this secondary analysis, mixed effects models and Generalized Estimating Equations were used to assess postictal changes in mean fractional anisotropy (FA) and mean diffusivity (MD), including relations with reorientation time and occurrence of postictal agitation. Additionally, with Tract-Based Spatial Statistics (TBSS), voxel-wise changes in the white matter (WM) skeleton were examined.</div></div><div><h3>Results</h3><div>Postictal agitation, but not reorientation time, was associated with decreased mean FA (<em>β =</em> −12.0, <em>OR =</em> 0.70, <em>p</em> = 0.02). This relationship was supported by voxel-wise analysis, that revealed associations with postictal FA reduction localized in the left anterior limb of the internal capsule. Additionally, postictal agitation was associated with increased mean MD (<em>β =</em> 1.02e⁴, <em>OR =</em> 1.42, <em>p</em> = 0.04) in white matter. No significant associations were observed with baseline values of MD or FA.</div></div><div><h3>Conclusions</h3><div>We show that postictal agitation is associated with brain-wide immediate postictal diffusivity changes, suggesting a clinically relevant role of changes in tissue microstructure shortly after an ECT-induced seizure.</div></div>","PeriodicalId":9206,"journal":{"name":"Brain Stimulation","volume":"19 2","pages":"Article 103031"},"PeriodicalIF":8.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145997364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transcranial alternating current stimulation can disrupt or reestablish neural entrainment in parkinsonian motor cortex","authors":"Harry Tran ,&nbsp;Biswaranjan Mohanty ,&nbsp;Noah Hjelle ,&nbsp;Zhihe Zhao ,&nbsp;Sangjun Lee ,&nbsp;Adele DeNicola ,&nbsp;Ivan Alekseichuk ,&nbsp;Miles Wischnewski ,&nbsp;Jing Wang ,&nbsp;Jerrold Vitek ,&nbsp;Luke Johnson ,&nbsp;Alexander Opitz","doi":"10.1016/j.brs.2026.103045","DOIUrl":"10.1016/j.brs.2026.103045","url":null,"abstract":"<div><h3>Background</h3><div>In Parkinson's disease, motor network electrophysiology frequently exhibits excessive beta oscillations. The cornerstone of therapeutic efficacy lies in the ability to modulate these pathological oscillations. Transcranial alternating current stimulation (tACS), a non-invasive method that applies oscillating electric fields to modulate ongoing brain activity, offers a promising approach.</div></div><div><h3>Objective</h3><div>The objective of the manuscript is to investigate the dose-dependent effects of tACS on motor network cortical neurons in a Parkinson's disease model.</div></div><div><h3>Methods</h3><div>We recorded neuronal spike activity in the motor cortex in parkinsonian non-human primates during tACS to determine how stimulation-induced electric fields affect spike timing.</div></div><div><h3>Results</h3><div>Strong electric fields entrained neural activity at the stimulation frequency but altered the preferred spiking phase. Conversely, weak fields disrupted beta-band synchronization by modulating spike timing and phase preference. Frequency-matched stimulation significantly enhanced entrainment when aligned with endogenous oscillatory activity.</div></div><div><h3>Conclusion</h3><div>Thus, with appropriately chosen stimulation parameters, tACS exhibits significant potential for controlling and modulating pathological oscillatory patterns that are characteristic of many neurological disorders.</div></div>","PeriodicalId":9206,"journal":{"name":"Brain Stimulation","volume":"19 2","pages":"Article 103045"},"PeriodicalIF":8.4,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146117955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hybrid optogenetic and electrical stimulation of retinal ganglion cells for artificial vision","authors":"William C. Kwan ,&nbsp;Emma K. Brunton ,&nbsp;Toon Goris ,&nbsp;James M. Begeng ,&nbsp;Tatiana Kameneva ,&nbsp;Paul R. Stoddart ,&nbsp;Michael R. Ibbotson ,&nbsp;Rachael T. Richardson ,&nbsp;Wei Tong","doi":"10.1016/j.brs.2025.103012","DOIUrl":"10.1016/j.brs.2025.103012","url":null,"abstract":"<div><h3>Introduction</h3><div>Millions of adults worldwide experience severe visual impairment due to photoreceptor loss from retinal diseases such as retinitis pigmentosa and macular degeneration. Retinal prostheses that provide artificial vision by stimulating the surviving retinal ganglion cells (RGCs) have emerged as a promising therapy. However, all clinically approved retinal prostheses that use electrical stimulation face the issue of electrical spread. As such, the quality of restored vision provided by existing devices has been limited. Optogenetic approaches provide greater spatial precision, however, they have poor temporal properties compared to electrical stimulation.</div></div><div><h3>Materials and methods</h3><div>We developed an opto-electrical hybrid approach and surveyed this stimulation strategy in the retina of two animal models: normal-sighted transgenic mice that express ChR2-H134R in a sub-population of RGCs and the degenerated retina of Royal College of Surgeons rats with residual RGCs transduced with ChrimsonR. We conducted whole-cell patch clamp recordings and measured calcium transients with the biosensor GCaMP7s to determine single-cell and population responses to hybrid stimulation, respectively.</div></div><div><h3>Results</h3><div>Hybrid stimulation reduced both electrical and optogenetic activation thresholds. Optical thresholds could be halved with electrical supplementation and synergistically, the opto-electrical coupling reduced the electrical intensity requirements to elicit action potentials by ∼50 % (p &lt; 0.0001). Additionally, hybrid stimulation evoked significantly higher firing frequencies, by an order of up to 2×, when compared to electrical or optical-only methods (p &lt; 0.0001). These properties of hybrid stimulation were replicated in the diseased retina, where the reduced activation thresholds contributed to significantly reduced spread of activation compared to electrical stimulation alone (p &lt; 0.05), a challenge that persists in devices that utilize extracellular electrical stimulation. Hybrid stimulation improved the spatial resolution of RGC activation when applied at retina-electrode spacing reflective of current epiretinal and suprachoroidal devices.</div></div><div><h3>Conclusion</h3><div>Combining the optogenetic and electrical modes of activation enabled significant reductions of each component in the stimulus, leading to more localised stimulation when compared to electrical-only stimulation, while also reducing the optical intensity required for optogenetic activation. Together with improvements in response reliability, hybrid stimulation may not only improve the resolution and refresh rate of future visual prostheses but may also provide greater control in neuromodulation for any bionic device that interfaces with neural tissue.</div></div>","PeriodicalId":9206,"journal":{"name":"Brain Stimulation","volume":"19 1","pages":"Article 103012"},"PeriodicalIF":8.4,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145826907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}